Flashcards in Rectal Disorders Deck (27)
What is the dentate line?
a ring of folds 2 cm from the anal verge where the anal canal meets the rectum - it delineates where nerve fibers end (above the line, the area is insensitive to pain, below, the anal canal and anus are extremely sensitive)
Where do veins from the rectum and anus drain?
portal vein (which leads to the liver and then the general circulation)
Where do the lymph vessels of the anorectal area drain?
rectum -> lymph nodes in the lower abdomen; anus -> lymph nodes in the groin
What are the segments of the lower digestive tract (in order starting from the anus)?
anus, rectum, sigmoid colon, descending colon, transverse colon, ascending colon, cecum, illeum, jejunum, duodenum
What are hemorrhoids?
dilated, twisted (varicose - swelling and tortuous lengthening) veins located in the walls of the rectum and anus
How are hemorrhoids classified?
internal (above the dentate line - venous return is portal) versus external (below dentate line - venous return is systemic)
What type of bleeding can occur with hemorrhoids?
arterial - via the presinusoidal arterioles
Where is the anorectal junction?
above the anal columns (which are above the dentate line)
How are internal hemorrhoids classified?
By the degree to which they prolapse from the anal canal:
Grade I: do not prolapse below dentate line
Grade II: prolapse but reduce spontaneously
Grade III: prolapse and require manual reduction
Grade IV: are irreducible and may strangulate
What are the major causes of hemorrhoids?
constipation (most common), prolonged straining, pregnancy, heredity, increased intra-abdominal pressure, aging
What are the symptoms of hemorrhoids?
bleeding (bright red if internal or darker if external) on stool or in toilet, mucosal protrusion, discharge, soiled underwear, sensation of incomplete evacuation, pain (only if thrombosed - uncommon with internal but common with external)
What is the treatment for hemorrhoids?
sitz baths, moist heat, suppositories, stool softeners, bed rest, stool bulking agents (psyllium/Metamucil or methylcellulose/Citrucel), surgery, banding
What is an anal fissure?
longitudinal or elliptical tear in the anoderm distal to the dentate line
What are the three types of anal fissures?
acute (appears like fresh laceration - erythematous), chronic (raised edges and fibrotic appearance - discoloration), underlying disease
What are the causes of anal fissure?
primary (local trauma, passage of hard stool, high anal pressure) or secondary (inflammatory bowel disease, malignancy)
What is elevated resting hypertonia of the internal anal sphincter?
higher max and mean resting anal pressures lead to higher levels of tonic contraction of the IAS ("tight ass" - high strung personality)
What are the treatments for anal fissure?
four weeks of fiber, stool softeners, increased water intake, sitz baths, topical analgesic, topical vasodilator (0.2% nitroglycerin paste/nifedipine on peri-anal area 3-4 times per day)
What are the cardinal features of hemorrhoids?
painless bleeding (bright red, coating stool), mild fecal incontinence, mucus discharge, anal pruritus, prolapse, pain (due to thrombosis)
What are the differential diagnoses of hemorrhoids?
anal fissure, solitary rectal ulcer syndrome, polyps, rectal prolapse, colorectal/anal cancer, proctitis
When should you refer for hemorrhoids?
melena, postural vital sign abnormalities, symptoms suggestive of malignancy, positive fecal occult blood, family Hx of cancer, change in bowel habits
What is the most common location for an anal fissure?
posterior anal midline
What are the presenting features of anal fissures?
tearing pain with passage of bowel movements, bright rectal bleeding, perianal pruritis, skin irritation
What are the distinctions between acute and chronic anal fissures?
acute - appears like fresh laceration, superficial, heals in about 6 weeks; chronic - has raised edges, white/horizontally oriented fibers, accompanied by skin tags/papillae, may require surgical repair
What are the differential diagnoses of anal fissures?
perianal ulcers (cause by IBD, granulomatous diseases, and STIs), anorectal fistula, solitary rectal ulcer syndrome
What are some preventive measures for anal fissures?
proper anal hygiene, keeping anal area dry (towel or blow dry with hair dryer on low setting), wiping with soft cotton or moistened cloth, preventing constipation, avoiding straining, avoiding trauma, prompt treatment of diarrhea
What would be the differential diagnosis of an anal fissure found other than at the posterior midline?